Ergo Program and Assessment Tools

Transcription

1 Ergo Program and Assessment Tools Kenny Young, CSP, ARM, AINS, CEAS Director of Safety Services 1 Goals Develop a basic understanding of ergonomics Identify when to use specific ergonomic assessment tools Understand the limitations of each ergonomic assessment tool Use the OSHA W 1 checklist, WISHA checklist, RULA, REBA, Liberty Mutual Tables, NIOSH Lifting Equation, and EJMS for ergonomic assessments to calculate risk and make meaningful interventions 2 1

2 What Is Ergonomics? Modify people to fit the equipment? or Modify jobs to fit capabilities of people? Reduce Musculokeletal Disorders (MSD) Repetitive reaching, forceful exertions, bending and lifting, or working with vibrating equipment 33% of all injury and illness cases for BLS 3 4 2

3 OSHA Regulation of Ergonomics General Duty Clause Applies to unregulated hazards Failure to keep a hazard-free workplace Hazard recognized by employer or employer s industry Hazard could cause death or serious harm Method existed to correct the hazard 5 What Are MSD s Injuries to: Muscles Nerves Tendons tendonitis Ligaments Joints Spinal discs Bursa Muscles, tendons, and bones work together as a level and pulley system. 6 3

4 MSD Characteristics Single event or many small injuries (acute v. chronic)? Weeks, months, or years to develop Produce no symptoms in early stages, but show symptoms after permanent injury has occurred Same MSD may differ in severity from person to person doing a similar task Posture + Force + Repetition = MSDs 7 Common MSDs Carpal tunnel syndrome Low back pain Eye strain Tendinotis Trigger finger 8 4

5 Risk Factors that Lead to MSDs Frequency/Repetitive motions Forceful exertions Awkward postures Contact stress (pressure points) Vibrations 9 Risk Factor Repetitive Motion and Frequency Repetitive motion requires prolonged use of a muscle or muscle group Muscle will fatigue and may eventually become damaged if not allowed to rest Repetition defined as: Muscle groups involved are repeatedly doing the same motions, or Entire cycle is completed in 30 seconds for 2 consecutive hours, or Mouse or input device use is steady for 4 consecutive hours Workplace Clues Working through breaks doesn t allow body to recover Working at machine pace no ability to self determine rest period 10 5

6 Duration Duration usually need hours of exposure before risk factors become a concern Can be all at one time or cumulative over the day Job rotation 11 Forceful Exertions Inflammation of tendons, nerves, joints Contributing factors Type of grip Weight of object Body posture Type and duration of the task Repeatedly turning a screwdriver while pushing at the same time Image Credit: OSHA 12 6

7 Hand and Wrist Information Straight Wrist: 100% strength Awkward wrist posture can reduce grip strength by Halfway Bent: 65 to 75% strength Fully Bent: 15 to 20% strength Pinch v. Power grip A pinch grip produces 3-5 times more force on the tendons in the hand and wrist. A 1 1/2-2 inch diameter is the ideal power grip. 1 1/2 14 7

8 Awkward Postures Stress on muscles and tendons Contributing factors Reaching overhead Force the body must maintain to hold the position Holding fixed positions (static loading) Lifting while twisting, reaching, or turning Injuries occur when muscles and joints are not positioned optimally 15 Awkward Posture Hand and Wrist Awkward Posture RADIAL DEVIATION NEUTRAL ULNAR DEVIATION EXTENSION NEUTRAL FLEXION 16 8

9 Head & Neck Postures? Best degrees Low Stress Position 0 to 20 degrees High Stress Position 21 deg and > 17 Back and upper Body Postures? Low Stress - Back Flexion 0 29 degrees High Stress - Back Flexion 30 deg and > 18 9

10 Awkward upper body posture 22 Problem 11 example: Lifting Guidelines (in pounds) Health and Safety Executive (1992) Manual Handling: Guidance on regulations, Solution example: 19 Shoulder Related Risk Factors Reaching above shoulder level Reaching behind the back Reaching forward Prolonged suspension of the arm

11 Shoulder Related Risk Factors A worker s elbow position relative to his/her shoulder and relative to the location where pressure is applied can produce pain and injury: Elbows above shoulder Hands above head. 21 Elbow Related Risk Factors Repetitive elbow bending Wrist bending with force Working with the elbows < 90 degrees Working with palms up or down Gripping with arms extended Resting arms on hard surface Palm-up Palm-down 22 11

12 Elbow Information Open jar (elbows near 90 ) When someone hands you a tight jar to open, you naturally hold it with your elbows at 90 People are not very strong applying a torque (twisting) force with the hands Turn Screwdriver Static Posture Static posture occurs when one position is held for a prolonged period of time The muscles will become fatigued from a lack of blood flow during a static posture This fatigue can lead to discomfort and even injury 24 12

13 Contact Stress Pressing against or grabbing a hard object puts pressure on nerves, tendons, and blood vessels Contributing factors Repetition Duration of contact Grip strength required 25 Vibration Affects tendons, muscles, joints, nerves Contributing factors Prolonged grip Restricts blood supply to hands and fingers Tools without vibration dampening device Poor power tool maintenance Prolonged use of a grinder 26 13

14 Vibration Exposure to vibration can occur while using power tools or while driving equipment Vibration from power tools can place stress on the tissues of the fingers, hands and arms Whole body vibration from driving puts stress on the back 27 Vibration Moderate vibration High vibration 28 14

15 Temperature Exposure to high or low temperature ranges which are also affected by ambient air, or surface temperature (of tools, etc.). High temperatures create whole body fatigue. Low temperatures slow blood flow which hinders recovery and may lead to Raynaud s Syndrome ( white fingers disease ). 29 INJURY DATA ANALYSIS EMPLOYEE AWARENESS TRAINING EMPLOYEE ENGAGEMENT MANAGEMENT COMMITMENT COST- BENEFIT ANALYSIS ERGONOMICS PROGRAM RISK ASSESSMENT AND RE-ASSESSMENT COST OF WORKPLACE INJURIES WORKPLACE DESIGN RISK FACTOR IDENTIFICATION PROGRAM IMPLEMENTATION 30 15

16 EXAMPLES OF SUCCESSFUL ERGONOMIC PROGRAMS 31 GOODYEAR In 1986, Goodyear established an ergonomics element in their safety program including: Awareness training Established ergonomics committee Established an audit program Fixed identified problems Geras, DT et al,. (1989). Advances in Industrial Ergonomics and Safety, I. London: Taylor & Francis

17 Geras, DT et al,. (1989). Advances in Industrial Ergonomics and Safety, I. London: Taylor & Francis. GOODYEAR S ACCIDENT RATES BEFORE & AFTER ERGONOMICS PROGRAM PROGRAM IMPLEMENTED mid year 33 Wisconsin Aluminum Foundry Foundry has approx. 390 employees Implemented safety & ergonomics inspections Fixed identified problems RESULTS: WC costs reduced by 76.6% over 2 years Positive reports from employees Foundry Ergonomics Partnership Helps Employers Improve Safety and Efficiency. (n.d.). Retrieved December 7, 2008, from Occupational Health and Safety Administration Web Site:

18 IMPROVEMENT I Installed lift and tilt tables for baskets of parts and conveyors Reduced lifting Reduced bending and reaching Increased productivity Parts on lift basket Facility 8 Foundry Ergonomics Partnership Helps Employers Improve Safety and Efficiency. (n.d.). Retrieved December 7, 2008, from Occupational Health and Safety Administration Web Site: 35 IMPROVEMENT II Installed a core lump crusher to eliminate the use of jackhammers to break up air set cores from casting Reduced bending Reduced exposure to vibration Facility 7 Foundry Ergonomics Partnership Helps Employers Improve Safety and Efficiency. (n.d.). Retrieved December 7, 2008, from Occupational Health and Safety Administration Web Site:

19 IMPROVEMENTS III Installed hydraulic opening system on permanent mold dies Reduced strain Reduced fatigue Less burn cases Increased productivity Foundry Ergonomics Partnership Helps Employers Improve Safety and Efficiency. (n.d.). Retrieved December 7, 2008, from Occupational Health and Safety Administration Web Site: 37 WHERE DO YOU START? 38 19

20 Where do you start? STEP 1: Review injury history STEP 2: Evaluate workplace STEP 3: Implement improvements STEP 4: Engage employees STEP 5: Re evaluate, measure improvements 39 STEP 1: Review Injury History REVIEW OSHA recordable incidents First Aids/Near Misses WHY OSHA recordables = actual incidences First aids/near misses = potential incidences / injuries 40 20

21 OSHA 300 Logs & Incidence Rate OSHA 300 Logs Date of injury Employee name Job Title Injury location (department) Body area affected Type of injury Death/ Days away/ Lost time 41 EXAMPLE: OSHA 300 LOG RESULTS Injury By Job Title Injury By Location Injury By Body Area Job Title 2008 Location 2008 Body 2008 Saw Operator 5 Saw 5 Leg 1 Caster 10 Sand Cast 10 Arm & Hand 4 Finisher 3 Finishing 3 Back 9 Packer 1 Packing 1 Shoulder 3 Fork Truck Driver 1 Warehouse 1 Eye OSHA 300 Logs are the first level of information 42 21

22 EXAMPLE: CALCULATIONS PER JOB TITLE Total Percent number of injured Job Title 2008 employees Saw Operator % Caster % Finisher % Packer % Fork Truck Driver % Let s calculate the percentage of injured employees by their job title How does this change the perspective? 43 EXAMPLE: BODY AREA PER JOB TITLE Use details to identify the rootcause(s) Focus proper resources to generate preventative measures 44 22

23 EXAMPLE: SAW OPERATOR Highest % injuries Review eye and arm/hand protection Job Title 2008 Saw Operator Total employees Percent injured % Body Saw Operator Leg Arm & Hand 3 Back Shoulder Eye 2 Total 5 45 EXAMPLE: CASTER Highest number of injuries for the given year/period of time Review individual incidents for the root cause and for any other potential contributing factors Body Caster 2008 Leg 1 Arm & Hand 4 Back 7 9 Shoulder 3 3 Eye 3 Total

24 SUGGESTIONS FIRST: Create a spreadsheet Use spreadsheet to track/organize information Share information with managers & employees THEN: Injury Data Analysis Create charts and graphs to look for trends Modify standard operating procedures Improve employee training programs 47 QUESTIONS? 48 24

25 Reduce the risk of injury STEP 1: Review injury history STEP 2: Evaluate workplace STEP 3: Implement improvements STEP 4: Engage employees STEP 5: Re evaluate, measure improvements 49 HOW DO YOU FIX SOMETHING? Hammer Nails Level Tape measure Screw driver Screws Tape And more 50 25

26 STEP 2: EVALUATE WORK ENVIRONMENT Tools Qualitative Semi Quantitative Quantitative Checklists 51 BENEFITS OF EVALUATION Determine risk level of the jobs Prioritize which jobs to improve Target areas within a job to improve Allow for Before & After analysis 52 26

27 Qualitative Methods Analysis is based on a checklist of job risk factors Follows two paths: Professional judgment Experience Supplementary knowledge of the injury and accident history is helpful 53 Qualitative Methods Advantages: Simplicity Speed Disadvantages: Limited conditions of applicability Require some training and ergonomic experience Can be very inconsistent Superficial and sometime insufficient results 54 27

28 Qualitative Methods Tool(s) covered in this training: OSHA W 1 Screening tool checklist WISHA checklist Examples of other tools in this category: PLIBEL 55 Checklists The person or team using a checklist considers whether a particular job risk factor is present in the job Depending on the checklist used, there will be considerations of: Strength Fatigue Cumulative trauma disorders (CTD) Environment 56 28

29 CHECKLIST ANALYSIS ORIENTATION Body regions Back and legs Hand and wrists Elbows Shoulders and neck Type of work Manual handling Lifting and lowering Pushing and pulling Workstation design Etc. Conditions Posture Repetition Force Environment Etc. 57 Semi Quantitative Methods Semi quantitative tools require: More focused screening of specific job risk factors, usually distinguished by risk to a specific body region More effort to collect and process data Follows two paths: Qualitative assessment Professional judgment May consider more than one contributing factor 58 29

30 Semi Quantitative Methods Tool(s) covered in this training: RULA REBA EJMS Examples of other tools in this category: Rodgers Muscle Fatigue Assessment Strain Index 59 Quantitative Methods Quantitative tools: Require more effort and expertise Help to understand how job risk factors combine in order to assess risk Suggest contributing factors to control Based on static or dynamic strength criterion 60 30

31 Quantitative Methods Tool(s) covered in this training: NIOSH Lifting Equation Liberty Mutual Manual Materials Handling Tables (Snook Tables) Examples of other tools in this category: ilmm 2D or 3D Static Biomechanical Analysis 61 Tools OSHA checklist WISHA checklist RULA REBA Liberty Mutual Tables NIOSH Lifting Equation EJMS 62 31

32 OSHA W 1 Screening tool Checklist Overview Ratings Either the risk factor is present or not Considers (in general categories) Awkward postures (some by body part, some in groups) Repetition, duration, vibration Force: pounds lifted, contact stress Specific section for computer workstations Easy to understand = Great for ergonomics teams! 63 Tools Needed Protractor 64 32

33 OSHA W 1 Screening tool Checklist Example Refer to the checklist in your workbook 65 Tools OSHA checklist WISHA Checklist RULA REBA Liberty Mutual Tables NIOSH Lifting Equation EJMS 66 33

34 WISHA Checklist Overview Ratings Either the risk factor is present or not Checklist for caution zones and hazard zones Considers (in general categories) Awkward postures (some by body part, some in groups) High hand force Highly Repetitive Motion Repeated Contact Vibration Easy to understand 67 WISHA Does address combination of risk factors Great first cut ergonomic tool Draw Backs High sensitivity: identify many jobs Doesn t separate frequency component by body part 68 34

35 Tools Needed Stopwatch 69 Using WISHA 3 basic sections Entire body checklist Lifting hazard section Vibration hazard analysis Entire body checklist Identify if a particular hazard exist as a result of a risk factor for a body part If a hazard exists then corrective action is needed 70 35

36 Lifting hazard analysis Using WISHA Calculated weight limit is adjusted by: Compares the actual weight lifted to a calculated weight limit Actual weight lifted > Weight limit = Hazard exists 71 Using WISHA Vibration hazard analysis Compares the time an employee uses the machine to a pre measured vibration value Plot time vs. vibration data on graph Intersection point indicates degree of hazard Vibration data:

37 Tools OSHA checklist WISHA Checklist RULA REBA Liberty Mutual Tables NIOSH Lifting Equation EJMS 73 RULA Overview Rapid Upper Limb Assessment Ratings Multiple levels, assigns a score Considers by body part Static and dynamic work Posture Duration Force: pounds lifted, surface contact Focused on upper extremities (upper limbs) 74 37

38 Tools Needed Worksheet Protractor Scale 75 RULA 6 Steps 1. Observe the task and interview employee Photos vs. video 2. Select postures for assessment Most difficult Most frequent Highest force loads 3. Score the postures 4. Process the scores 5. Determine final score 6. Confirm action level 76 38

39 RULA Survey method Assess postures of neck and upper limb loading Best for sedentary, seated tasks Final risk assessment score Combines arm/wrist risk with neck, trunk, leg risk Final score magnitude (between 1 and 7) Overall injury risk due to musculoskeletal loading 77 RULA One of most popular ergonomic assessment tools in industry User friendly, charts can be confusing Only evaluate one arm at a time Not as good for determining risk due to repetition No major calculations needed, quick Validated 78 39

40 RULA

41 81 RULA Action Level Final RULA Scores Requirements for Action 1 or 2 Indicates that posture is acceptable if it is not maintained or repeated for long periods. 3 or 4 Indicates that further investigation is needed and changes may be required. 5 or 6 Indicates investigation and changes are required soon. 7 Indicates investigation and changes are required immediately

42 Steps 1 4: Arm & Wrist Analysis

43 85 Steps 9 11: Neck, Trunk, and Leg Analysis 86 43

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45 89 RULA Action Level Final RULA Scores Requirements for Action 1 or 2 Indicates that posture is acceptable if it is not maintained or repeated for long periods. 3 or 4 Indicates that further investigation is needed and changes may be required. 5 or 6 Indicates investigation and changes are required soon. (likely risk of injury) 7 Indicates investigation and changes are required immediately. (immediate risk of injury) 90 45

46 Tools OSHA checklist WISHA Checklist RULA REBA Liberty Mutual Tables NIOSH Lifting Equation EJMS 91 REBA Same principles as RULA, validated Better tool for whole body Static, dynamic, unstable or rapidly changing postures User friendly, tables used to compute scores Good for health care & service industries Not as useful for production line work 92 46

47 Tools Worksheet Protractor Scale

48 Steps 1 3: Neck, Trunk, and Leg Analysis

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51 Score Level of MSD Risk 1 Negligible risk, no action required 2 3 Low risk, change may be needed 4 7 Medium risk, further investigation, change soon 8 10 High risk, investigate and implement change 11+ Very high risk, implement change

52 Tools OSHA checklist WISHA Checklist RULA REBA Liberty Mutual Tables NIOSH Lifting Equation EJMS 103 Liberty Mutual Manual Materials Handling Tables Originally published by Snook in 1978 and by Snook and Ciriello in 1991 Provide both the male and female population percentages capable of performing manual material handling tasks without overexertion This is not maximum acceptable weights and forces Used to perform ergonomic assessments of lifting, lowering, pushing, pulling, and carrying tasks with the primary goal of supporting ergonomic design interventions

53 Tools Needed Tape Measure Stop Watch 105 Measurements Hand Distance = distance from the front of the body to the hands Different measurement from the NIOSH model Lifting Distance = Hand height at end of task subtracted by hand height at start of task Frequency = the average time between handling individual objects

54 Measuring Pushing/Pulling Tasks Will need a spring scale, a load cell or other force measurement device and enter the initial force, in pounds, needed to start the object moving. If using a spring scale device, you can measure the force by pulling. Although different effects on the body, measured force is the same. Obtain sustained force measurement to keep the object moving 107 Measurements Many measurements will lie between table values. Round to the higher or lower value depending on whether the value is above or below the middle value of the measurement

55 Using the Tables/Results Rule of thumb designing manual tasks for greater than 75% of the female work population will offer the best protection from manual handling injuries. Tasks having population percentages of less than 10% should be prioritized for task redesign Used for what if scenarios of various ergonomic interventions 109 Caution on Using the Tables Injuries Jobs producing injuries are good candidates for redesign Bending Tasks that begin or end with hands below knuckle height present some degree of risk. Deeper the bending, greater the stress to the low back. Frequent bending regardless of weight is not recommended. Twisting This motion puts uneven forces on the back thereby presenting additional physical stress. Greater the twist, the more stressful on the back

56 Caution on Using the Tables Reaching The distance away from the body that a load is held greatly affects the forces on the back, shoulders, and arms. The farther the reach, the more stressful the task. One Handed Lifts Tables cannot be used to evaluate one handed tasks. These tasks place uneven loads on the back and greater stress. Hand holds Inability to get a good grip on the load presents greater stress. Catching/Throwing Tables cannot evaluate these tasks. 111 Liberty Mutual Tables Refer to tables in your workbook MTablesWeb/taskSelection.do?action=initTaskSelect ion

57 Tools OSHA checklist WISHA Checklist RULA REBA Liberty Mutual Tables NIOSH Lifting Equation EJMS 113 NIOSH Lifting Equation NIOSH National Institute for Occupational Safety and Health Lifting/lowering tasks Does not consider: One handed lifts Team lifts Patient handling Pushing, puling, holding, carrying, walking Lifting/lowering for over 8 hours Lifting/lowering while seated Lifting/lowering while kneeling Lifting/lowering in an adverse environment (hot, cold, humid, etc)

58 NIOSH Lifting Equation Compares initial location of load to final location Rating: Lifting Index Considers: Posture Duration Frequency Position of the load Asymmetry (twisting) Weight/force of the load Coupling 115 Tools Needed Tape Measure Scale

59 NIOSH Lifting Equation Recommended = 51 x HM x VM x DM x AM x FM x CM Weight Limit (RWL) Metric U.S. LC - Load Constant 23 Kg 51 lbs HM - Horizontal Multiplier (25/H) (10/H) VM - Vertical Multiplier (1-(.003 V-75 )) (1-(.0075 V-30 )) DM - Distance Multiplier (.82+(4.5/D)) (.82+(1.8/D)) AM - Asymmetric Multiplier (1-(.0032A)) same FM - Frequency Multiplier see table see table CM - Coupling Multiplier see table see table 117 H - destination V - destination H - origin V - origin

60 Are the H & V values always taken for the origin and destination? H - destination V - destination H - origin V - origin 119 No, only when significant control is required to place the object in its final destination. H - destination V - destination H - origin V - origin

61 NIOSH Lifting Equation Horizontal Multiplier - HM... (10/H) Is the horizontal distance from hands to midpoint between the ankles. H inches HM H inches HM H inches HM < NIOSH Lifting Equation Vertical Multiplier - VM... (1-(.0075 V-30 )) Is vertical distance from floor to hands as the object is grasped. Measure from start of lift to stop of lift V inches VM V inches VM V inches VM >

62 NIOSH Lifting Equation Distance Multiplier - DM... (.82+(1.8/D)) The vertical distance traveled by the hands between object s origin (start) and destination (stop) D inches DM D inches DM D inches DM < > NIOSH Lifting Equation Asymmetric Multiplier - AM... (1-(.0032A)) The degree of deviation/twist from the sagittal plane. A degrees AM A degrees AM >

63 NIOSH Lifting Equation Frequency Multiplier - FM... see table The average number of lifts per minute over a 15-minute period. The FM combines the VM, lifts per minute, and allowed recovery to actual work. 125 NIOSH Lifting Equation To define the Work Duration for the FM, identify the frequency of lifts to allowed recovery... according to: Short Duration... continuous lifting up to one hour followed by recovery at least 120% of the work time. Moderate Duration... continuous lifting up to 2 hours followed by recovery at least 30% of the work time. Long Duration... continuous lifting up to 8 hours with no additional allowance for recovery

64 F lifts/ min. Frequency & Duration Values < 1 hour 1-2 hours 2-8 hours V < 30 inv > 30 inv < 30 in. V > 30 inv < 30 in. V > 30 in. < > NIOSH Lifting Equation Coupling Multiplier - CM... see table Quality of the grasp on an object or container during a lift. Coupling Quality V<30 inches V>30 inches Good Fair Poor

65 Object To Be Lifted Containerized Well Designed? yes Optimal Handles? yes no no yes POOR no 90 deg.? yes FAIR GOOD Loose Material Bulky? no Optimal Grip? no yes NIOSH Lifting Formula Job Analysis Worksheet Co/Dept. Date Analyst s Name Job Title Task Description Object Weight (lbs) TASK MEASUREMENTS Hand Location Task Angle Coupling origin dest. Freq. of V<30 in.or V>30 in. H V H V per/min. Asymmetry Good Fair Poor Recommended Weight Limit Lifting Index - LI RWL in (lbs.) LI = Actual Load Weight / destination

66 Recommended Weight Load RWL = LC x HM x VM x DM x AM x FM x CM 131 NIOSH Lifting Equation Once the RWL is determined, you can then compute the Lifting Index (LI) to estimate the hazard of overexertion in any specific job. LI = LOAD WEIGHT (L) RECOMMENDED WEIGHT LIMIT * An LI exceeding 1.0, indicates that reengineering is appropriate in rank order to other, more hazardous lifting jobs

67 NIOSH Lifting Index Weight RWL = LI LI < 1 1< LI < 3 LI > 3 Safe Increased Risk Not Safe When using the NIOSH lifting equation no worker should be performing a task with a lifting index greater than 3! 133 Basic Solution Alternatives If the HM is less than 1.0, consider designs which improve the Safety of each lift as needed. Remove horizontal barriers, or reorient the object closer to the carrier. Reduce the object size being handled which reduces its awkwardness

68 Basic Solution Alternatives If the VM is less than Avoid lifting at or near the floor level. Provide designs or alternative equipment which raise or lower the object as needed to reduce vertical movement. 135 Basic Solution Alternatives If the DM is less than Reduce the vertical distance which an object must travel to its destination location. Provide alternative design or equipment which raise or lower the object to effectively reduce vertical movement

69 Basic Solution Alternatives If the AM is less than Redesign the workstation to eliminate unnecessary rotating (this should also improve productivity). Emphasize and enforce appropriate lifting procedure to staff during material handling procedures. 137 Basic Solution Alternatives If the FM is less than Lower the frequency of required lifts. Reduce the lifting duration... if not possible by engineering means, consider job rotation, or enlargement. Provide for longer recovery periods between lifting sessions

70 Basic Solution Alternatives If the CM is less than Provide containers which enhance the available grip on loose, flowable objects. Include handles with proper design and durability... temporary carriers or cut outs may be options. 139 Basic Solution Alternatives If the RWL is less at the destination than at the origin... Redesign the workstation to eliminate the need for Significant Control at the destination. Improve the objects/container characteristics to make it easier to grasp and handle which enhances the CM factor

71 Tools OSHA checklist WISHA Checklist RULA REBA Liberty Mutual Tables NIOSH Lifting Equation EJMS 141 Tools OSHA checklist WISHA Checklist RULA REBA Liberty Mutual Tables NIOSH Lifting Equation EJMS

72 EJMS See EJMS handout and discuss 143 Ergonomics at Work - Reducing heavy lifting Mechanical assistance

73 Ergonomics at Work - Reducing gripping force Tool Balancer/Manipulator

74 Ergonomics at Work - Reducing high work Fixture lift for overhead applications 147 Ergonomics at Work - Reducing reaching Tilt table for sanding

75 Ergonomics at Work - Reducing reaching Tilt table to Reduce Bending of Neck and Back 149 Ergonomics at Work - Reducing low work Raise and tilt the work

76 151 Angular Material Positioning Carousel Tilting Stand Tilting Cart

77 Ergonomics at Work - Reducing low work Raise the Work 153 Keep the Load off the Floor Pallet Lifter Pallet Stand Height Adjustable Cart Scissors Lift

78 Tools Manipulators can reduce Stress! 155 Ergonomics at Work - Reducing bent wrists Re-orient the Object

79 Reducing Vibration Use low vibration tools if available Maintain tools Cut Resistant 2 Anti Vibration By Superior Glove Use anti vibration gloves or tool wraps Keep hands warm 157 SUMMARY Repetitive tasks are usually easier to evaluate Multi task jobs OR jobs with longer cycles are more difficult to evaluate Every evaluation tool has strengths and weaknesses Ergonomic workplace evaluations are a multi step process Every tool considers ideal conditions, i.e. comfortable environment, healthy employees

80 RULA Employee Assessment Worksheet Task Name: Date: A. Arm and Wrist Analysis Step 1: Locate Upper Arm Position: Scores B. Neck, Trunk and Leg Analysis Step 9: Locate Neck Position: Neck Score Step 1a: Adjust If shoulder is raised: +1 If upper arm is abducted: +1 If arm is supported or person is leaning: -1 Step 2: Locate Lower Arm Position: Upper Arm Score Step 9a: Adjust If neck is twisted: +1 If neck is side bending: +1 Step 10: Locate Trunk Position: Step 2a: Adjust If either arm is working across midline or out to side of body: Add +1 Step 3: Locate Wrist Position: Lower Arm Score Step 10a: Adjust If trunk is twisted: +1 If trunk is side bending: +1 Step 11: Legs: If legs and feet are supported: +1 If not: +2 Trunk Score Leg Score +1 Step 3a: Adjust If wrist is bent from midline: Add +1 Step 4: Wrist Twist: If wrist is twisted in mid-range: +1 If wrist is at or near end of range: +2 Step 5: Look-up Posture Score in Table A: Using values from steps 1-4 above, locate score in Table A Step 6: Add Muscle Use Score If posture mainly static (i.e. held>10 minutes), Or if action repeated occurs 4X per minute: +1 Step 7: Add Force/Load Score If load <.4.4 lbs. (intermittent): +0 If load 4.4 to 22 lbs. (intermittent): +1 If load 4.4 to 22 lbs. (static or repeated): +2 If more than 22 lbs. or repeated or shocks: +3 Step 8: Find Row in Table C Add values from steps 5-7 to obtain Wrist and Arm Score. Find row in Table C. Wrist Twist Score Wrist Score Posture Score A + Muscle Use Score + = Add +1 Force / Load Score Wrist & Arm Score Scoring: (final score from Table C) 1-2 = acceptable posture 3-4 = further investigation, change may be needed 5-6 = further investigation, change soon 7 = investigate and implement change RULA Score Step 12: Look-up Posture Score in Table B: Using values from steps 9-11 above, locate score in Table B Step 13: Add Muscle Use Score If posture mainly static (i.e. held>10 minutes), Or if action repeated occurs 4X per minute: +1 Step 14: Add Force/Load Score If load <.4.4 lbs. (intermittent): +0 If load 4.4 to 22 lbs. (intermittent): +1 If load 4.4 to 22 lbs. (static or repeated): +2 If more than 22 lbs. or repeated or shocks: +3 Step 15: Find Column in Table C Add values from steps to obtain Neck, Trunk and Leg Score. Find Column in Table C. Posture B Score + Muscle Use Score + Force / Load Score = Neck, Trunk, Leg Score Original Worksheet Developed by Dr. Alan Hedge. Based on RULA: a survey method for the investigation of work-related upper limb disorders, McAtamney & Corlett, Applied Ergonomics 1993, 24(2), 91-99

81 REBA Employee Assessment Worksheet Task Name: Date: A. Neck, Trunk and Leg Analysis Step 1: Locate Neck Position Scores B. Arm and Wrist Analysis Step 7: Locate Upper Arm Position: Step 1a: Adjust If neck is twisted: +1 If neck is side bending: +1 Step 2: Locate Trunk Position Neck Score +4 Step 7a: Adjust If shoulder is raised: +1 If upper arm is abducted: +1 If arm is supported or person is leaning: -1 Step 8: Locate Lower Arm Position: Upper Arm Score Step 2a: Adjust If trunk is twisted: +1 If trunk is side bending: +1 Step 3: Legs Adjust: Add +1 Add +2 Step 4: Look-up Posture Score in Table A Using values from steps 1-3 above, Locate score in Table A Posture Score A Step 5: Add Force/Load Score + If load < 11 lbs. : +0 If load 11 to 22 lbs. : +1 If load > 22 lbs.: +2 Adjust: If shock or rapid build up of force: add +1 Force / Load Score Step 6: Score A, Find Row in Table C Add values from steps 4 & 5 to obtain Score A. Find Row in Table C. Scoring 1 = Negligible Risk 2-3 = Low Risk. Change may be needed. 4-7 = Medium Risk. Further Investigate. Change Soon = High Risk. Investigate and Implement Change 11+ = Very High Risk. Implement Change Trunk Score Leg Score = Score A + Table C Score Activity Score REBA Score = Step 9: Locate Wrist Position: Step 9a: Adjust If wrist is bent from midline or twisted : Add +1 Step 10: Look-up Posture Score in Table B Using values from steps 7-9 above, locate score in Table B Step 11: Add Coupling Score Well fitting Handle and mid rang power grip, good: +0 Acceptable but not ideal hand hold or coupling acceptable with another body part, fair: +1 Hand hold not acceptable but possible, poor: +2 No handles, awkward, unsafe with any body part, Unacceptable: +3 Step 12: Score B, Find Column in Table C Add values from steps 10 &11 to obtain Score B. Find column in Table C and match with Score A in row from step 6 to obtain Table C Score. Lower Arm Score Wrist Score Posture Score B Step 13: Activity Score +1 1 or more body parts are held for longer than 1 minute (static) +1 Repeated small range actions (more than 4x per minute) +1 Action causes rapid large range changes in postures or unstable base + Coupling Score = Score B Original Worksheet Developed by Dr. Alan Hedge. Based on Technical note: Rapid Entire Body Assessment (REBA), Hignett, McAtamney, Applied Ergonomics 31 (2000)

82 NIOSH Lifting Equation Data Collection Sheet Department: Job Title: Analyst's Name: Date: Job Description: MODEL INPUTS Horizontal Location Origin (in.) = Horizontal Location Destination (in.) = Vertical Location Origin (in.) = Vertical Location Destination (in.) = Vertical Travel Distance (in.) = Angle of Asymmetry Origin (degrees) = Angle of Asymmetry Destination (degrees) = Frequency (lifts per minute) = Duration (hrs) = Coupling (good, fair, or poor) = Weight of Object (lbs.) = Additional Loss Control Resources are available at our website:

83 Horizontal Location Origin / Destination Horizontal Location is the distance of the hands (in inches) from the vertical plane of the midpoint of the ankles. The diagram below illustrates how to measure the horizontal location. Perform this measurement at the starting point (origin) and ending point (destination) of the lift. Vertical Top View Point of Projection Horizontal Horizontal Location H Lateral Mid-Point Between Inner Ankle Bones V Vertical Location Horizontal Mid-Point Between Inner Ankle Bones H Horizontal Location Point of Projection Graphic Representation of Hand Location

84 Vertical Location Origin / Destination Vertical Location is the distance of the hands (in inches) from the plane of the floor. The diagram below illustrates how to measure the vertical location. Perform this measurement at the beginning (origin) and end (destination) of the lift. On the entry screen, select the vertical location from the drop-down list that is closest to the actual vertical location (i.e., 32 inches = 30; 33 inches = 35). Vertical Top View Point of Projection Horizontal Horizontal Location H Lateral Mid-Point Between Inner Ankle Bones V Vertical Location Horizontal Mid-Point Between Inner Ankle Bones H Horizontal Location Point of Projection Graphic Representation of Hand Location

85 Vertical Travel Distance Vertical travel distance is the distance the hands travel between the origin and destination of the lift. On the entry screen, select the vertical travel distance from the drop-down list that is closest to the actual distance traveled. Angle of Asymmetry Origin / Destination Angle of Asymmetry is the displacement angle of the load from the sagittal or median plane of the body. In other words, it is the number of degrees the back and body trunk must twist or rotate to accomplish the lift. The diagram below illustrates how to measure the angle of asymmetry. Perform this measurement at the beginning (origin) and end (destination) of the lift. On the entry screen, select the angle of asymmetry from the drop-down list that is closest to the actual angle of asymmetry (i.e., 20 degrees = 15; 25 degrees = 30). Top View Frontal Point of Projection A Sagittal H Mid-Point Between Inner Ankle Bones Frequency Rate Frequency Rate is measured in the number of lifts performed each minute. In situations where less than one lift is performed each minute, the frequency rate will be less than 1 (e.g., one lift every five minutes = 0.2 lifts/minute). Duration Duration is the length of time the worker performs the lifting task. Duration is either classified as short (1 hour or less), moderate (1-2 hours), or long (2-8 hours).

86 Coupling Coupling is the classification that affects how much force is required to grip the object to complete the lifting task. Coupling quality is classified as good, fair, or poor. The table below describes how to determine the coupling quality of the object being lifted. Hand-to-Container Coupling Classification GOOD FAIR POOR 1. For containers of optimal design, such as boxes, crates, etc., a "Good" hand-to-object coupling would be defined as handles or hand-hold cutouts of optimal design. 2. For loose parts or irregular objects, which are not usually containerized, such as castings, stock, and supply materials, a "Good" hand-to-object coupling would be defined as a comfortable grip in which the hand can easily be wrapped around the object. 1. For containers of optimal design, a "Fair" hand-toobject coupling would be defined as handles or hand-hold cut-outs of less than optimal design. 2. For containers of optimal design with no handles or hand-hold cut-outs or for loose parts or irregular objects, a "Fair" hand-toobject coupling is defined as a grip in which the hand can be flexed about 90 degrees. 1. Containers of less than optimal design or loose parts or irregular objects that are bulky, hard to handle, or have sharp edges. 2. Lifting non-rigid bags (i.e., bags that sag in the middle). NIOSH Lifting Equation Constraints The NIOSH Lifting Equation does not apply if any of the following occur: Lifting/lowering with one hand. Lifting/lowering for over 8 hours. Lifting/lowering while seated or kneeling. Lifting/lowering in a restricted work space. Lifting/lowering unstable objects. Lifting/lowering while carrying, pushing, or pulling. Lifting/lowering with wheelbarrows or shovels. Lifting/lowering with high-speed motion (faster than 30 inches/second). Lifting/lowering with unreasonable foot floor coupling (<0.4 coefficient of friction between the sole and the floor). Lifting/lowering in an unfavorable environment (i.e., temperature significantly outside of degree F range; relative humidity outside 35-50% range.